Fair Value Measurements (Narrative) (Details) - USD ($)  | 
3 Months Ended | 9 Months Ended | 
|---|---|---|
Sep. 30, 2020  | 
Sep. 30, 2020  | 
|
| Fair Value Measurements [Abstract] | ||
| Transfers between levels | $ 0 | $ 0 | 
| X | ||||||||||
- Definition Amount of transfer of financial instrument between levels of the fair value hierarchy. No definition available. 
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| X | ||||||||||
- References No definition available. 
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